                      Takes 1 argument - wheel rotation, an int.
                      Negative values if the mouse wheel was rotated
                      up/away from the user, and positive values
-                     if the mouse wheel was rotated down/ towards the user
+                     if the mouse wheel was rotated down/towards the user
 
    :key-pressed    - Called every time any key is pressed.
 

  sketch
  "Create and start a new visualisation applet.

   :size           - a vector of width and height for the sketch or :fullscreen.
                     Defaults to [500 300].

   :renderer       - Specify the renderer type. One of :p2d, :p3d,
                     :java2d, :opengl, :pdf). Defaults to :java2d.

   :features       - A vector of keywords customizing sketch behaviour.
                     Supported features:

                     :keep-on-top - Sketch window will always be above other
                                    windows. Note: some platforms might not
                                    support always-on-top windows.

                     :exit-on-close - Shutdown JVM  when sketch is closed.

                     :resizable - Makes sketch resizable.

                     :no-safe-draw - Do not catch and print exception in the
                                     draw fn. By default all exceptions thrown
                                     inside draw function are catched so sketch
                                     doesn't break if something goes wrong.

                     :present - Switch to present mode (fullscreen without
                                borders, OS panels). You may want to use this
                                feature together with :size :fullscreen.

                     Usage example: :features [:keep-on-top :present]

